"no wireless networks found " at random times

My network sometimes (without reason) goes down and from that time it is not possible to restart it unless I reboot the laptop.

It just says: "no wireless networks found". I have tried to restart wicd and the network but no result.

I have tried also to do a sudo iwlist scan, tried to do a ifconfig wlan0 up with no success. I have got messages such as: "SIOCSIFFLAGS: Invalid argument" and "wlan0 Interface doesn't support scanning : Network is down".

I have tried also to rmmod and modprobe ath5k (my network card is an Atheros) and other modules but still nothing.

Any other idea?

Cheers!

Edit: I don't rimember the first time I got this problem (not less than 5 6 months)

Re: "no wireless networks found " at random times

Can you bring your wireless back up by unloading / reloading the module?

# modprobe -r ath5k
# modprobe ath5k

I was getting random disconnects and slowdowns (on an Intel chip) due to the devilish combination of poor ipv6 handling and wireless N - displayed similar symptoms to what you are experiencing, however

There are effective fixes on the wiki for both situations - could be used to discount those particular issues if nothing else

Re: "no wireless networks found " at random times

Can you bring your wireless back up by unloading / reloading the module?

# modprobe -r ath5k
# modprobe ath5k

I was getting random disconnects and slowdowns (on an Intel chip) due to the devilish combination of poor ipv6 handling and wireless N - displayed similar symptoms to what you are experiencing, however

There are effective fixes on the wiki for both situations - could be used to discount those particular issues if nothing else

Re: "no wireless networks found " at random times

Hello!

I've experienced similar problems with suddenly vanishing atheros wlan-card. (AR2427) It pointed out to a problem with the power management setting which causes this behaviour when set to 'on'.Once fallen in sleep-mode after some time IDLE the card won't wake up any more and is 'gone' till you manually bring it up again.

By setting 'Power Management:off' permanently for the card using an udev rule or LaptopModeTools the problem was gone for me.

Re: "no wireless networks found " at random times

renegat wrote:

Hello!

I've experienced similar problems with suddenly vanishing atheros wlan-card. (AR2427) It pointed out to a problem with the power management setting which causes this behaviour when set to 'on'.Once fallen in sleep-mode after some time IDLE the card won't wake up any more and is 'gone' till you manually bring it up again.

By setting 'Power Management:off' permanently for the card using an udev rule or LaptopModeTools the problem was gone for me.

Hi!

Thanks for your advice!

So I have to disable the Power management just for the card, not the power management in general, right?